The invention relates to carbon spheres or fullerenes based on thirty six carbon atoms, and more particularly to solid state materials formed of these fullerenes and methods of making same.
The discovery in 1985 of a new form of carbon, the pure carbon cage molecule C60, known as the “Bucky Ball” or [Buckminster]fullerene, initiated a new class of materials. In its molecular form C60 is a highly spherical hollow cage molecule with the carbon atoms in the shell arranged in a network of pentagons and hexagons. In the experimentally observed and energetically most favorable “soccer ball” configuration, all twelve pentagons are isolated. Since C60 is the smallest fullerene obeying the isolated pentagon rule, there were questions about the stability of smaller pure carbon cage molecules formed from pentagons and hexagons since they must necessarily contain adjacent pentagons with a resultant large energy strain. Subsequently, a number of different size fullerenes have been synthesized in small amounts.
Under appropriate nonequilibrium growth conditions, carbon atoms form relatively stable hollow clusters of well-defined mass number, collectively known as fullerenes. The mass production of these clusters, and their purification and condensation into a solid are essential to full characterization and utilization of these new materials. While gas phase experiments indicate a wide range of fullerenes, beyond C60 only a few pure fullerene solids have been obtained, notably C70.
Lower mass fullerenes are of particular interest because their high curvature and increased energy strain owing to adjacent pentagon rings could lead to solids with unusual intermolecular bonding and electronic properties. These structures are expected to display chemical, electronic, magnetic and mechanical properties significantly different from, and possibly technologically more important than the more conventional C60 fullerenes.